Method of winding helical springs and device for effecting the same

ABSTRACT

The winding of helical springs is effected by bending successive portions of a wire by segments of a circle. In order to form the above segments, the successive portions of the wire are squeezed on a support, in which case the wire and the support are mutually rotated and displaced forward. The wire should be squeezed by striking the wire or subjecting the wire to impacts in the same place of the support. The method is carried into effect by a device having a support and a striker reciprocating relative to the support. The striker is mounted with a gap relative to the support and the wire is fed into this gap during the operation of the device. Thus, the striker strikes the wire periodically to form the segments, from which the coils of the spring are then formed.

ilnited States Patent 91 Nazyrov et al.

[ 51 May 22,1973

154] METHOD OF WINDING HELICAL SPRINGS AND DEVICE FOR EFFECTING THE SAME [76] Inventors: Ravil Nigametzhanovich Nazyrov, ulista Gagarina, 63, kv. 36; Rinad Fatkhrakhmanovich Kavirov, ulista Saidasheva, 42, kv. 7, both of Kazan, U.S.S.R.

[22] Filed: Feb. 25, 1971 [21] Appl. No.: 118,636

[52] U.S. Cl ..140/71 R, 72/135,140/102 [51] Int. Cl. ..B2li 3/02 [58] Field of Search ..140/71, 86, 92, 105;

[56] References Cited UNITED STATES PATENTS 2,276,579 3/1942 Halvorsen et al ..72/l35 2,776,678 1/1957 Savage ...140/105 3,045,740 7/1962 Davis ..l40/7l 3 340,238 3/1966 Sjobohm ..l40/71 Primary Examiner-Lowell A. Larson Attorney-Holman & Stern [57] ABSTRACT The winding of helical springs is effected by bending successive portions of a wire by segments of a circle. in order to form the above segments, the successive portions of the wire are squeezed on a support, in which case the wire and the support are mutually rotated and displaced forward. The wire should be squeezed by striking the wire or subjecting the wire to impacts in the same place of the support.

The method is carried into effect by a device having a support and a striker reciprocating relative to the support. The striker is mounted with a gap relative to the support and the wire is fed into this gap during the operation of the device. Thus, the striker strikes the wire periodically to form the segments, from which the coils of the spring are then formed.

6 Claims, 8 Drawing Figures METHOD OF WINDING HELICAL SPRINGS AND DEVICE FOR EFFECTING THE SAME BACKGROUND OF THE INVENTION The present invention relates to improvements in methods of and devices for winding springs of a wire. The invention may be used for making springs, particularly springs of a high curvature, and various configurations of a wire having a constant or variable cross sec tion. The invention is especially suitable for making conical, cylindrical or barrellike springs.

The method can be used for making helical springs having a curvature of C 4.0, where C is the ratio of the medium diameter of the spring to the diameter of the wire of which the spring is wound. Such springs find wide application in instrumentation, medical and radioelectronic devices.

PRIOR ART Widely known in the art is a method of making helical springs having a high curvature of the coil, which consists in the wire being wound about a mandrel, for example made of kapron. When the winding is completed, the mandrel is removed by dissolving it in a suitable solvent.

This method is disadvantageous in that the possibility of making shaped springs is very limited both due to the difficulties associated with the making of a shaped mandrel of an elastic material and to a variable outer diameter of the mandrel because of a considerable linear elongation factor of the elastic material. Furthermore, it should be noted that this method allows the mandrel to be used only once, and hence the cost of making the springs is considerably increased.

Also known in the art is another method of making springs of a small diameter (up to a few millimeters), according to which the wire is coiled about a metal mandrel having a diameter much smaller than the diameter of the wire being wound. When effecting this method, the mandrel is displaced from the spring under the action of the elastic compressive forces appearing during the winding of the springs.

This method is disadvantageous in that the removal of the mandrel from a spring having a variable diameter or from a spring having a considerable curvature (low value of C) is rather difficult and may lead to the deformation both of the spring and the mandrel.

These methods are effected by means of devices comprising mechanism for clamping and rotating the mandrel, a shuttle mechanism for displacing the wire, a winding head consisting of a sleeve with a radial slot for passing the wire into the sleeve which is disposed coaxially to the mandrel. The winding head holds the spring coils on the mandrel and guides the wire to the mandrel during the winding.

However, such a device limits the possibility of winding shaped springs particularly of a wire having a variable cross section as the inner diameter of the sleeve aperture and the width of the slot are constant. At the same time, a sleeve of a variable cross section can not practically be used.

OBJECTS AND SUMMARY OF THE INVENTION An object of the present invention is to provide a possibility of winding springs of any configuration of a wire of any cross section and to simplify the process of making such springs.

Another object of the invention is to strengthen the surface of the springs directly in the process of winding.

The above and other objects are attained in that, according to the present method of winding helical springs, each spring coil is formed by bending the successive portions of the wire by segments of a circle, with the segments being formed by squeezing the successive portions, while the overlapping them, on a support during mutual rotary and forward movement of the wire and the support.

In such a method of winding, each portion of the spring can be removed from the support, so that the mandrel limiting the possibility of making shaped springs is no longer necessary.

It is expedient in the process of mutual displacement of the support and the wire, to squeeze the wire by striking it in the same place of the support for forming the segments.

The method can be carried into effect by means of a device which, according to the invention, comprises a support and a striking mechanism with a striker recip rocating relative to the support and periodically striking a wire fed into a gap between the support and the striker for forming the segments of the spring coil in the process of multiple cooperation striking actions of the striker and the wire.

To provide the conditions of striking the wire in the same place of the support, the support is preferably interconnected with the striking mechanism for mutual displacement therewith. In this case, the striking mechanism may be made in the form of a double-arm lever, one arm of which interacts with a follower whose shape determines a frequency and amplitude of the oscillations of the other arm on which there is mounted the striker of the striking mechanism reciprocating relative to the support.

To control the distance between the support and the striker in the process of winding the spring, the support is mounted on one arm of the double-arm lever, with the other arm thereof interacting with a shaped cam. Such making of the winding device is most expedient for manufacturing springs having a variable diameter.

To control the angle of inclination of the winding, the support is mounted on a base capable of turning in a plane normal to the winding plane, in which case the striker and the support may be interconnected through spring-loaded pins.

Further objects and advantages of the invention will be apparent from the following description of the method and device for wounding a conical spring by way of example with reference to the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view in perspective of a portion of the device for carrying the proposed method into effect;

FIGS. 2a-2d are diagrammatic views illustrating various stages of forming the segments of a spring coil;

FIG. 3 is a diagrammatic view showing the formation of a spring coil from the segments;

FIG. 4 is a perspective view partly in elevation and partly in cross-section of the device for winding springs according to the invention and;

FIG. 5 is a perspective view showing the striking mechanism and the support in the device of FIG. 4.

DETAILED DESCRIPTION OF THE DRAWINGS Described below is a method of winding springs for medical stomatological channel fillers having a conical shape with a thickened tail.

The tail of a blank 1 (FIG. 1) is clamped in a holder 2 so that the tail axis coincides with the axis of rotation of a shaft 3, on which are mounted a prismatic support 4, a striker 5 and a guide plate 6. The other end of the blank 1 made in the form of a conical wire is bent approximately at an angle of 90 to the longitudinal axis of the wire and is passed into a slot of the guide plate 6 so that the portion of the wire from which the spring coils are initiated is placed into a gap between the support 4 and the striker 5.

The shaft 3 is rotated and displaced forward along its own axis. In this case, the striker 5 is reciprocated in a radial direction, as shown by the arrows, until it strikes or subjects the wire to impacts, thus effecting bending of the wire by segments. When winding shaped springs, the support is also displaced in a radial direction along the plane normal to the winding plane so that it is moved to and from this axis, while being turned about an axis normal to the winding plane by the predetermined angle of helix of the spring coil.

The process of forming separate segments of a wire is shown in FIGS. 2a2d.

The end of the blank 1 is passed through the gap (FIG. 2a) between the support 4 and the striker 5 so that the wire portion, where the spring winding is initiated, intersects the axis 00. In this case, the thickened end of the blank 1 is clamped in the holder 2 and the blank is rigidly fixed during the winding operation.

The support is installed at some distance from the shaft axis and, then the striker 5 is forced to strike the blank (FIG. 2b). In this case the linear portion of the wire having a length Al (FIG. 2a) is bent into a segment Al (FIG. 2b). At the next moment, the striker 5 and the support 4 are turned through a certain angle Aa(FIG. 2c) about the axis of the shaft 3, with the striker 5 being simultaneously moved to the initial position corresponding to the position in FIG. 2a. In this case, the angle of rotation Act of the striker and the support and the width of the radial portion r of the striker are selected so that the length of the segment Al (FIG. 2b) always exceeds the linear length of the portion of the circular displacement of the radial portion of the striker 5 when turning it through the angle Aa. Thus, during the next striking action of the striker 5 on the wire the next segment A1 is bent, which segment consists of a linear portion A1 (FIG. 2d) which is always less than the portion Al and a curvilinear portion Al which is also less than the portion A1,, i.e., each next striking of the blank is effected with a partial overlapping of the segments.

FIG. 3 shows a spring coil formed during a single complete revolution of the striker and the support.

The device for performing the above method includes the shaft 3 mounted on the base thereof and connected to an electric motor 8 through a pulley and belt drive 7. Rigidly secured on the shaft 3 is a housing 9 carrying double-arm levers l0 and 11 mounted on 'axles 12 and 13 respectively. In the housing 9, the support 4 (FIGS. 4 and 5) is loosely mounted on an axle 14, while the striker 5 is connected to the support 4 through guide pins 15 loaded with cushioning springs 16. In the same housing there is mounted the guide plate 6 rigidly connected to the support 4. The support 4 is rotated by means of a kinematic system 17 secured on the housing 3 and automatically turning the support 4 through a predetermined angle. The shaft 3 loosely passes through an axial aperture of a cup-type replaceable cam 18 (FIG. 4) secured on the base of the device. The cup cam 18 has outer and inner profiles. The outer profile is fluted and is run by the end of the double-arm lever 10, while the inner profile thereof is smooth and is run by the end of the lever 11.

The shaft 3, through toothed gears 19, 19a and gear 20 and rack 20a, is connected with a follower rule 21 one end of which is hinged. The operating profile of this rule is in constant contact with a follower 22 transmitting an axial displacement to the shaft 3 through a roller 23 loosely mounted on the axle of the follower 22 and a disk 24 rigidly mounted on the shaft 3. The holder 2 is used for clamping the thickened tail of the blank 1 and is secured on the base of the device so that its axis coincides with the axis of the shaft 3.

The device operates as follows:

When the electric motor 8 is activated, the shaft 3 is rotated through the drive 7. In this case, the striker 5 displaces in a radial direction and reciprocates in a plane perpendicular to the shaft axis under the action of the lever I10 running along the outer profile of the cam 18. At the same time, the shaft 3 displaces forward in an axial direction under the action of the toothed gears 19, 19a and 20, 20a, the follower rule 21, the follower 22, the roller 23 and the disk 24.

As previously mentioned, the thickened end of the tail of the blank 1 is clamped in the holder 2 so that the tail axis coincides with the axis of rotation of the shaft 3, while the opposite end of the blank 1 in the form of a conical wire is bent approximately at an angle of so that the portion of the wire, where the winding of the spring is to be started, is fed into the gap between the support 4 and the striker 5.

When the shaft 3 is rotated, one arm of the lever 11 slides along the smooth surface of the cam 18, while the other arm displaces the support 4 along the axle 14 (if a shaped spring is wound). At the same time, one arm of the lever 10 slides along the fluted surface of the cam 18, while the other arm of this lever reciprocates, whereby the striker 5 strikes the wire forming segments thereon, so that the coils of the spring are gradually formed from these segments as above described.

The predetermined pitch of the coil is provided by an axial forward displacement of the housing 9 simultaneously with the shaft 3 under the action of the follower rule and the toothed gear arrangement.

The predetermined angle of the helix of the spring coil is automatically maintained by the kinematic system 17. This system operates as follows:

In the process of winding the support depresses a heel 25 (FIG. 5) of an angular bracket 26 loosely mounted on an axle 27. The angular bracket 26, through a lever system, turns the support and the striker 5 through a predetermined angle, in which case a spring coil is formed.

While the process above described is for making conical springs, it is to be noted, however, that the process of winding springs having another geometry and made of a wire of a various shape is similar to the abovedescribed process.

The above description is directed to only one embodiment of the device for effecting the proposed method, but, other modifications are possible. For example, the striking mechanism may be actuated by an electromagnetic, hydraulic, pneumatic or another drive, while the rotary motion may be imparted to the blank instead of the shaft.

The use of the present invention allows the process of winding to be improved, while the efficiency of the process is increased by a factor of 5 as compared with the known methods and the life of the spring is increased by a factor of 1.5 to 2.0 due to a strengthening of the outer surface of the spring by the strikes.

We claim:

1. A method of winding helical springs of a wire com prising forming each coil of the spring by bending successive portions of the wire by segments of a circle, in which the segments are formed by striking the successive portions of the wire on a support while effecting a relative mutual rotation and forward displacement of said wire and said support.

2. The method as claimed in claim 1, during which in the mutual displacement of the wire and the support the wire is struck in the same place on the support for forming said segments.

3. A device for winding helical springs of a wire in which each coil of the spring is formed by bending successive portions of the wire by segments of a circle,

comprising a clamp for holding one end of the wire, a support, a striking mechanism, having a striker mounted having a striker mounted within a gap between the striker and said support, said striker reciprocating relative to said support and periodically striking the wire fed into the gap between said support and said striker for forming a spring coil during multiple coacting strikings of the striker and the support, and a drive for effecting a relative mutual reciprocating displacement of the wire and the support to feed the successive portions of the wire into the gap.

4. The device as claimed in claim 3, in which the support and striking mechanism are connected for mutual displacement and the striking mechanism includes a double-arm lever one arm of the lever interacting with a follower, the shape of the follower determining a fre quency and an amplitude of oscillations of the other arm of the lever on which is mounted the striker of the striking mechanism reciprocating relative to the support.

5. The device as claimed in claim il, in which the support is mechanically connected to one arm of the double-arm lever, and the other arm of the lever interacting with a shaped cam to control the distance between the support and the striker.

6. The device as claimed in claim 5, in which the sup port is arranged on a base to be capable of turning in a plane normal to the winding plane, and said striker and said support being interconnected through spring- 

1. A method of winding helical springs of a wire comprising forming each coil of the spring by bending successive portions of the wire by segments of a circle, in which the segments are formed by striking the successive portions of the wire on a support while effecting a relative mutual rotation and forward displacement of said wire and said support.
 2. The method as claimed in claim 1, during which in the mutual displacement of the wire and the support the wIre is struck in the same place on the support for forming said segments.
 3. A device for winding helical springs of a wire in which each coil of the spring is formed by bending successive portions of the wire by segments of a circle, comprising a clamp for holding one end of the wire, a support, a striking mechanism, having a striker mounted having a striker mounted within a gap between the striker and said support, said striker reciprocating relative to said support and periodically striking the wire fed into the gap between said support and said striker for forming a spring coil during multiple coacting strikings of the striker and the support, and a drive for effecting a relative mutual reciprocating displacement of the wire and the support to feed the successive portions of the wire into the gap.
 4. The device as claimed in claim 3, in which the support and striking mechanism are connected for mutual displacement and the striking mechanism includes a double-arm lever one arm of the lever interacting with a follower, the shape of the follower determining a frequency and an amplitude of oscillations of the other arm of the lever on which is mounted the striker of the striking mechanism reciprocating relative to the support.
 5. The device as claimed in claim 4, in which the support is mechanically connected to one arm of the double-arm lever, and the other arm of the lever interacting with a shaped cam to control the distance between the support and the striker.
 6. The device as claimed in claim 5, in which the support is arranged on a base to be capable of turning in a plane normal to the winding plane, and said striker and said support being interconnected through spring-loaded pins. 